The present invention is related to a power supply unit for use in a hybrid vehicle or an electric vehicle and a busbar module which is included in the power supply unit.
A power supply unit is mounted in an electric vehicle which is driven by use of an electric motor or a hybrid vehicle which is driven by use of an engine in combination with an electric motor for example, as a drive source of the electric motor (see, Patent Document 1). This power supply unit includes a battery unit and a busbar module. The battery unit is made up of a plurality of batteries, of which each battery has a positive electrode at one end and a negative electrode at the other end. The batteries are arranged neatly into a pile so that electrodes having different polarities are laid adjacent to each other. The busbar module is laid on an upper surface of the battery unit where the electrodes are provided. FIG. 11 is a top view of the related busbar module disclosed in Patent Document 1. FIG. 12 is an enlarged view of part of the busbar module shown in FIG. 11.
The busbar module 101 shown in FIGS. 11 to 12 includes a plurality of busbars 103 which connect the plurality of batteries of the battery unit, not shown, in series by connecting the electrodes of the batteries which are laid adjacent to each other, a plurality of terminals 104 which are connected individually to the busbars 103 for detecting a voltage of the batteries to which the busbars 103 connect, a plurality of electric wires 105 which are connected individually to the terminals 104, and a plate 106 which accommodates the plurality of busbars 103, the plurality of terminals 104 and the plurality of electric wires 105. In addition, an arrow X denotes a direction in which the plurality of batteries 20 are arranged neatly into a pile.
The plate 106 includes a plurality of primary plates 106A which are aligned in a straight line along an arrow X indicating a direction in which the plurality of batteries are aligned and a secondary plate 106B which is positioned at an end portion of the plurality of primary plates 106A. The plates 106A, 106B are connected together by the other ends of the plurality of electric wires 105 which are attached to the respective terminals 104 at the one end thereof being disposed from one primary plate 106A to the other plates 106A, 106B which are arranged adjacent to each other. Note that in FIG. 11, only one of the plurality of primary plates 106A is shown.
As shown in FIG. 11, the secondary plate 106B includes an electric wire fixing portion 107 which fixes the electric wires 105 which are disposed at an end portion of the secondary plate 106B which lies on a side lying farther away from the primary plate 106A. The electric wire fixing portion 107 has a rod-like shape. An adhesive tape is wound round outer circumferences of the electric wire fixing portion 107 and the plurality of electric wires 105 which are placed round the electric wire fixing portion 107, whereby the plurality of electric wires 105 are fixed to the electric wire fixing portion 107 that is the secondary plate 106B.
In the plates 106A, 106B of the related busbar module 101, the terminals 104 are attached to one end of each of the plurality of the electric wires 105, and the other ends of the plurality of electric wires 105 are arranged from the one primary plate 106A to the other plates 106A, 106B which are laid adjacent to each other, so that the plates 106A, 106B are connected. Thus, when only one of the plates 106A, 106B which are connected to each other is grabbed to be carried, the electric wire 105 which is arranged from the one to the other of the plates 106A, 106B is pulled. Accordingly, the electric wire 105 which is attached to the terminal 104 is removed from the terminal 104.
In addition, in the related busbar module 101, in fixing the electric wires 105 which are attached to the respective terminals 104, it is necessary to fabricate the secondary plate 106B on which the electric wire fixing portion 107 is provided. Consequently, two types of molds are needed. One of the molds is used for molding the primary plate 106A on which no electric fixing portion 107 is provided, and the other of the molds is used for molding the secondary plate 106B on which the electric wire fixing portion 107 is provided. Accordingly, the cost incurred in preparation of the molds is increased.
[Patent Document 1] JP-A-2008-166209